Graphite composite conductive bar material and method for producing graphene using the same

Abstract

A graphite composite conductive bar material and a method for producing graphene using the same are provided. The graphite composite conductive bar material is fabricated via mixing graphite powder more than 50% by weight with a polymeric material. The graphite composite conductive bar is used in a plasma electrochemical exfoliation process as a cathode and contacts with the surface of the electrolytic solution, whereby the bar material is exfoliated to obtain a less defective graphene. Therefore, the present invention can improve product yield and reduce production cost. In addition, a solid-state nitrogen-containing precursor may be added to the graphite composite conductive bar material for producing nitrogen-doped graphene. In the nitrogen-doped graphene produced by the present invention, the amount of doped nitrogen is increased and tunable compared to the former invention, and the level of oxidization is decreased.

What is claimed is: 
     
         1 . A graphite composite conductive bar material, functioning as a cathode in a plasma electrochemical process for producing graphene, wherein a plurality of graphite powders and a polymeric material are mixed and molded to form said graphite composite conductive bar material, and wherein said graphite composite conductive bar material contains more than 50 wt % of said graphite powders. 
     
     
         2 . The graphite composite conductive bar material according to  claim 1 , wherein said polymeric material is poly(methyl methacrylate) (PMMA). 
     
     
         3 . The graphite composite conductive bar material according to  claim 1 , wherein a proportion of said graphite powders is 50-85% of a total weight of said graphite composite conductive bar material, and a proportion of said polymeric material is 15-50% of said total weight of said graphite composite conductive bar material. 
     
     
         4 . The graphite composite conductive bar material according to  claim 3  further comprising a solid-state nitrogen-containing precursor. 
     
     
         5 . The graphite composite conductive bar material according to  claim 4 , wherein said solid-state nitrogen-containing precursor is melamine or polyaniline. 
     
     
         6 . The graphite composite conductive bar material according to  claim 4 , wherein a proportion of said solid-state nitrogen-containing precursor is less than 35% of said total weight of said graphite composite conductive bar material. 
     
     
         7 . A method for producing graphene, comprising steps:
 providing a graphite composite conductive bar material, wherein a plurality of graphite powders and a polymeric material are mixed and molded to form said graphite composite conductive bar material, and wherein said graphite composite conductive bar material contains more than 50 wt % of said graphite powders;   providing a plasma electrochemical apparatus including an electrolytic solution, an anode and a cathode, wherein said graphite composite conductive bar material is used as said cathode with one end thereof contacting said electrolytic solution; and   applying an electric potential difference between said anode and said graphite composite conductive bar material to make a surface of said graphite composite conductive bar material, which contacts said electrolytic solution, undertake a plasma electrochemical reaction to form graphene.   
     
     
         8 . The method for producing graphene according to  claim 7 , wherein said electrolytic solution is a strong acid or a strong base. 
     
     
         9 . The method for producing graphene according to  claim 7 , wherein said electric potential difference is more than 60V and an applied current is within 0.05-0.1 A. 
     
     
         10 . The method for producing graphene according to  claim 7 , wherein a contact area between said anode and said electrolytic solution is more than 20 times a contact area between said graphite composite conductive bar material and said electrolytic solution. 
     
     
         11 . The method for producing graphene according to  claim 7 , wherein said graphene is 1 μm in size and has 1-6 layers of carbon atoms. 
     
     
         12 . The method for producing graphene according to  claim 7 , wherein said graphene is a nitrogen-doped graphene with 1-4.6 at % doped nitrogen. 
     
     
         13 . The method for producing graphene according to  claim 7 , wherein said anode is made of a conductive inert metal. 
     
     
         14 . The method for producing graphene according to  claim 7 , wherein said polymeric material is poly(methyl methacrylate) (PMMA). 
     
     
         15 . The method for producing graphene according to  claim 7 , wherein a proportion of said graphite powders is 50-85% of a total weight of said graphite composite conductive bar material, and a proportion of said polymeric material is 15-50% of said total weight of said graphite composite conductive bar material. 
     
     
         16 . The method for producing graphene according to  claim 15 , wherein said graphite composite conductive bar material further comprising a solid-state nitrogen-containing precursor. 
     
     
         17 . The method for producing graphene according to  claim 16 , wherein said solid-state nitrogen-containing precursor is melamine or polyaniline. 
     
     
         18 . The method for producing graphene according to  claim 16 , wherein a proportion of said solid-state nitrogen-containing precursor is less than 35% of said total weight of said graphite composite conductive bar material.